The present invention is related to an anti-penetration structure of EL device, in which a voltage-durable layer is disposed between a front electrode layer and a lighting layer. The voltage-durable layer is able to enhance the voltage-durability of the EL device and prevent the lighting layer from being penetrated.
FIG. 2 shows a conventional electro luminescent (EL) device. The conventional EL device is composed of a transparent substrate 81, a front electrode layer 82, a lighting layer 83, an inducing layer 84, a back electrode layer 85 and an insulating packaging layer 86 which are sequentially overlaid on the transparent substrate 81. By means of applying an AC voltage between the front and back electrode layers 82, 85, the numerous lighting particles 831 of the lighting layer 83 are energized to emit light through the transparent substrate 81.
Due to structural or material factors, the lighting layer 83 has some shortcomings as follows:
1. The material has insufficient electricity-durability.
2. Bubbles are produced when manufacturing the lighting layer 83.
3. The alien materials or impurities in the solvent will contaminate the lighting layer 83.
4. The purity of the lighting material is insufficient.
5. The thickness of the material is uneven or holes are formed on the material.
Due to the above shortcomings, in dynamic test, instantaneous leakage of current will take place in the EL device to penetrate and burn down the lighting layer 83. This lowers the ratio of good product and increases manufacturing cost.
It is therefore a primary object of the present invention to provide an anti-penetration structure of EL device, in which a voltage-durable layer is disposed between the front electrode layer and the lighting layer. The voltage-durable layer is made of a mixture of more than one voltage-durable material and is able to enhance the voltage-durability of the EL device so as to prevent the lighting layer from being penetrated.
According to the above object, the anti-penetration structure of EL device of the present invention includes a transparent substrate, a front electrode layer, a lighting layer, an inducing layer and a back electrode layer, which are sequentially overlaid on the substrate. The lighting layer, inducing layer and back electrode layer are enclosed by an insulating packaging layer. A voltage-durable layer is disposed between the front electrode layer and the lighting layer. The voltage-durable layer is formed of a mixture of more than one voltage-durable material.